Paper article and method of forming it



Feb. 6, 1945. c. w. GOODWIN PAPER ARTICLE AND METHOD OF FORMING IT Original Filed Dec. 19, 1936 Sheets-Sheet 1 Feb. 6,. 1945. c. w. GOODWIN PAPER ARTICLE AND METHOD OF FORMING IT Origipal Filed Dec. 19 1936 2 Sheets-Sheet 2 I I INVENTOR Czr/ Manna/ ATTORNEB' Patentedi 'eb. 6, 1948 UNITED STATES' PATENT OFFICE PAPER ARTICLE AND METHOD OF FORMING IT Carl W. Goodwin, Piainileld, N.J., assignor to American Seal-Kap Corporation of Delaware, Wilmington, DeL, a corporation of Delaware,

Continuation of application Serial No. 116,705,

December 19, 1936. This 1942, Serial No. 43'L616 2 Claims.

7 ing or folding the paper into bead shape, it is made into an integral structure without separable laminations and is thus much stronger and bet ter able to withstand distorting forces than if such laminations were present. The capacity of the cap to withstand severe service is thus very greatly increased.

For a more complete understanding of this invention, reference may be had to the accompanying drawings in which Figure l is a central vertical section through the cap-forming portions of the forming dies.

Figure 2 is a horizontal section on line 2--2 of Figure 1.

Figure 3 is a fragmentary view partly broken away showing the cap applied to the top of a paper cup.

Figure 4 is a view similar to Figure 3, but showing the cap applied to a tumbler or glass.

Figures 5 to 8 inclusive are detail sections showing successive stages of the cap-forming operation.

Figure 9 is a plan view of a blank from which a somewhat modified form of cap may be made.

application April 4,

ing portion it of this plate 8 and is forced downwardly therethroug'h by the plunger 20 of the die i and onto-the base 8. This plunger 20 is provided with segmental portions 2|.and 22,.which, as shown best in Figure 2, are arranged in two sets having matinginclined faces 23. The segmental pieces 2| are shown as joined in pairs diametrically across the die I by means of springs which tend to hold these members in collapsed position in which condition also the portions 22 are still further retracted in the position shown in Figure 2. The portions 22, however, have inclinedinner upper faces 26 with which cooperate a frusto-conical portion 21 of an expanding block 28, so that as the block 28 is pushed downwardly relative to the members 2| and 22, both these ets of members are forced outwardly, the members 22 being moved out relative to the member 2| until their outer faces form with the outer faces of the portion 2i a continuous circumference.

Both the members 2i and 22 are provided with segmental portions of an annular rib 30, which,

Figure 10 is a view somewhat similar to Figure 3, but showing a cap made from the blank of Figure 9. This application is a continuation of my application Serial No. 116,705, filed December 19, 1936, for Paper article and method of forming it.

R ferring first to Figures 1, 2 and 3, at I and 2 are indicated cooperating dies. The lower die 2 comprises a socket member 3 in which is positioned a yielding base member ,4 which may be depressed against the pressure ofa spring 5 to the base of the socket with its upper face 6 substantially flush with the lower edge of a counterbored port on 1 at the upper end of the socket 3. At 8 is shown a plate member having an opening 9 therein flared at In, this plate member being movable to present in succession discs of paper to be formed between the dies I. and 2. The disc 01' paper when presented lies within the flarwhen these segments are expanded, form together a continuous rib about the lower end of the plunger 20. The first portion of the motion of the plunger 20 into the socket 3, carrying the central portion 'of the paper disc therewith, causes the marginal portion of the paper disc to be bent upwardly as shown at 40 in Figure 5, the central portion 4! of the disc being seated upon the base 6, the segmental portions 2i and 22 being then in expanded condition so that the flange 40 is engaged between the socket wall and the rib 30 adjacent ,to the face of the disc so as to support opposite faces of the flange 40 adjacent to the top surface of the disc. Above the rib 30 the flange 40 is supported only on its outer face, the outer wall of the plunger 20 above the rib 30 being spaced inwardly from the inside face of the flange 40. When the plunger has entered the socket sumciently far to seat the base member 4 against the base of the socket 3 into the position shown in Figure 6, the outer portion of the disc 40 just inwardly of the flange is seated on the base of the counterbored portion I, and an annular forming member 42 provided with a concave lower face 43 has engaged the upper edge of the flange- 40 and has upset and pressed it down endwise somewhat into the space 44 above the rib 30 and between the segments 2| and 22 and the wall of the socket 3, this space being substantially wider thanthe thickness of the paper stock, as is shown in Figures 5 and 6.

Engagement of the member 42 on the upper edge flange produces an upsetting action on the without seam or fold and molded into a bead configuration projecting inwardly from the outer wall of the flange and spaced from that portion of the article inwardly of the flange. On raising the die member I from the die member 2, the die parts are returned to their original position and the formed cap is removed from the vsocket 3, while the springs 25 act to retract the segmental portions, thus freeing the formed cap from the die member I.

. The die mechanism is not claimed herein but' forms subject matter of a co-pending application serial No. 53,897, for Molding mechanism, flled December 11, 1935, .now Patent 2,118,080, dated May 24, 1938.

In order to condition the paper stock so that it is capable of being upset and molded around its marginal flange and likewise to render it water-resistant or waterproof,it is desirable to pretreat it with moisture and a water-resisting compound such as wax. The treatment acts to temper the fibers and facilitates the molding operation and the compacting of the fibers together. Preferably along with the paraffln is included a. small percentage of a hardening wax such as carnauba or montan wax.

Such acap when formed may be snapped onto the top of a paper cup, such as shown in Figure 3,

provided with a marginal bead 50 at its upper edge, the molded bead portion 45 of the cap being.

snapped under this head on the cup. Likewise such a cap may be snapped over, the upper edge portion of a glass or tumbler, as shown in Figure 4, which may likewise be formed with athickened head portion 5! about its upper edge, or the cap may be engaged with the upper edge of a cup which flares slightly at its upper end rather than having any pronounced bead thereat, both flaring and a slight bead being shown in Figure 4. It will be noted from an inspection of Figures 3 and 4, that the bead 45 and its inward extension is small relative to the diameter of the cap. Thus the diameter of the cap in the clear between opposed portions of the inner edge of the head is less than that above the bead where it engages over the top of the container by such a small proportion of the total diameter that the bead may be stretched the very small amount necessary to snap the cover on or off the container,

the top of which is of slightly greater diameter than the interior of the bead and is of reduced diameter below its top, without opening up the structure of the bead or otherwise damaging it. If desired the cap may be sealed to the receptacle as by any suitable means such as a strip of cellulose compound shrunk thereover in accordance with well known practice.

By forming the marginal bead on the cap flange of highly compacted paper stock without fold or seam, it is capable of withstanding very severe service without being damaged and thus a very secure sealing of the contents of the cup or tumbler may be readily eifected.

In Figures 9 and 10 a modifled. construction has been illustrated. Where the bead 310 mm continuously (as in Fig. 4) around the entire circumference of the cap, the construction is quite rigid and when the container tops and caps are subject to much relative size variation, if these 7 caps are made small enough to have the required holding power on the smallest tops, it may be found very difllcult to force them onto the larger container tops without undue distortion or even collapse when the containers are made of very light and thin material as some types of paper drinking cups. This difficulty may be avoided by making the bead in separate segments. To this end the circular blanks 52 of Figure 9 from which the caps are to be made may be provided with the stock, which in the molding operation is formed into the head, so that the flange between the bead and the flange root where it joins the main body of the cap is continuous throughout its circumference. The molding operation brings the ends of the bead segments substantially togetherpr contiguous, as shown at 55 in Figure 10, but yet permits the bead segments to yield so as to take care of a larger variation in sizes of both-container tops and caps than could be done with acontinuous bead, while still providing an efiective seal. Caps so made are more flexible and easier to apply than those made with continuous beads.

From the foregoing description of the cap and its method of formation and mechanism for so forming it, it should be evident that various modifications and changes can be made without decup having a body'portion of flexible material and having an integral annular outer bead at its top, of a pre-formed snapon cover, which cover comprises a paper member having, prior to application to the container, a depending marginal flange'of an internal diameter at'least as great as the external diameter of said cup bead, said flange having a thickened portion forming a solid bead similar to the cup head on its inner peripheral face at its free edge of less vertical extent than said flange and spaced by said flange below the inner face of said cover a distance substantially equal to the vertical width of said cup bead for snap-on engagement -with the under surface of said cup bead to hold the under surface of the cover tightly against the top of the cup, the paper stock in said cover bead containing wax and being in a homogeneous seamless interfelted condition without seam or fold and being more highly less than the external diameter of said cup'bead that said cover may be snapped on and oil said cup without injury to or permanent deformation of said cover, said cover bead having peripherally spaced slits separating the sameinto contiguous segments to provide increased resilience for passing over said cup bead without causing deforma tion of said cup.

2. The combination with an open top nonmetalllc cup 9. body portion of flexible material and vhaving an integral annular outer bead at its top, of a pre-tormed snap-on cover, which cover comprises a paper member having, prior to application to the container, a depending marginal flange of an internal diameter at least as great as the external diameter of said cup bead, said flange having a' thickened portion forming a solid, integral bead similar to the cup bead on its inner peripheral face at its free edge of less vertical extent than said flange and spaced by said flange below the inner face of said cover a distance substantially equal to the vertical width of said cup head for snap-on engagement with the under surface of said cup bead to hold the under surface of the cover tightly against an internal diameter so little less than the extemal diameter of said cup head that said cover may be snapped on and of! said cup without injury to or permanent deformation of said cover.

CARL W. GOODWIN. 

